“Because you can feel them when they’re close,” I said. “The goosebumps on your skin even though it’s not cold. The way the air tastes, and the dry lump in your throat. That’s how they let you know they’re about to strike.”

“How do you get away?”

“No one ever has. You get about 10 minutes after you notice them before they force themselves inside you. Then it’s all over. Wait — did you feel something? Clara look at your arms! You’ve already got the goosebumps!”

My sister squirmed, thrashing against the seatbelt which suddenly looked like it was squeezing the breath out of her frail body. Her skin was bone-white, although that was hardly surprising since she never went outside.

I was doing my best to softly blow air on her from the corner of my mouth without her noticing it was me.

“Ghosts aren’t real, Clara. You’re 12-years-old — you should know better by now,” my dad said without turning. It had been a long drive for all of us, and he was gripping the wheel so tightly it looked like he was ready to swerve off the road and camp in the first ditch we found.

“See? I told you.” Clara crossed her arms in an infuriating display of smugness.

“Then how come dad’s mouth didn’t move when he said that?”

I’m almost ashamed to admit how much pleasure I got from her double-take. Almost. Then came the rapid, aggressive burst of tapping on the window and Clara actually shrieked. I couldn’t stop laughing as dad rolled down the window.

“Camping registration?” the park ranger asked, face shadowed by his wide-brimmed hat. He glanced disinterestedly into the back seats to catch Clara giggling and smacking me. She wasn’t strong enough for it to hurt, and I was laughing too so I didn’t bother defending myself. Mom looked tired, but peaceful.

“Thank God. I thought we’d never get here.” Dad handed the man an email printout.

“Long drive, huh? Where you folks from?” the ranger asked.

“California. I tried to tell them we have our own forests, but Clara was heart-set on seeing the great quaking aspen.”

“Welcome to Utah then. You won’t be disappointed. Did you kids know that the Pando is the oldest and biggest life form on the planet?”

“I did!” Clara raised her hand, flailing it around like an eager student. “Although each tree is only about 120 years old, they’re all connected to the same root network which has been alive for over 80,000 years, stretching over 105 acres.”

“Just 80,000?” The park ranger smirked. “I’ve heard it’s more like a million. We’re not sure exactly, but there’s a good chance the Pando was alive before the first human being walked the earth. Pretty incredible, huh?”

“Yep! I wish I could live that long.” Mom and dad exchanged furtive glances.

“It’s not about how long you live.” Mom’s voice cracked, and she had to take a long breath before she restarted. “It’s about what you do with the time that you have. And I for one am grateful for every second we get to spend together as a family.” Dad squeezed mom’s hand. It must have been hard too, because their interlocked fingers were trembling. The uncomfortable silence which followed only lasted a moment before the park ranger handed us a pass and waved us on our way.

It’s no secret that my sister is sick. Mom and dad don’t like to talk about it, so I didn’t know exactly what it was. She spent a lot of time in the hospital though, which seemed stupid to me because she was always weaker going out than she was going in. I’ve asked her about it before, but she just shrugged and said, ‘they’ll figure it out.’ I didn’t like the way her face looked when she said it, so I didn’t ask again. Seeing her scared like that wasn’t any fun.

It was almost dark when we got to the campsite. I helped dad setting up the tent while mom unpacked the car. Clara just sat on a log and stared at the sunset, which seemed really unfair to me, but it’s not like she’d be much help anyway. The light was weird here — even after the sun went down it didn’t really get dark. The twilight felt like it went on for hours, and the air was so quiet that time must have frozen. I was half-hoping Clara would pick up on the weird atmosphere and start believing in my ghosts again, but I think she’d forgotten all about them. Maybe she was never even afraid in the first place, only putting on a show for my amusement.

“Can you hear them?” she asked when I went over to call her for dinner.

“Who?”

“The trees. They’ve been waiting for me for a long time.”

I didn’t buy it. She was just trying to creep me out as revenge. “What are they saying?” I asked anyway.

Clara’s pale skin glowed in the enduring twilight, almost as white as her eerie smile. “It doesn’t speak with words. It’s more like feelings. Images. Ideas. The ‘Trembling Giant’ is angry. Slow, purposeful, smoldering, anger, like a glacier carving a hole in a mountain range. And it needs me to set it loose.”

I wish she wouldn’t smile like that. “Dinner’s ready, come on.” I turned back toward the fire in a hurry, not wanting to give her the satisfaction of seeing me shudder. Glancing back over my shoulder, I could still see the glow of her little teeth piercing the gathering dusk.

The next day was miserable and dull. I wanted to go out hiking and explore the forest, but Clara was too tired and mom insisted we don’t leave her behind. The whole point of this trip was to spend time together as a family, she said, so we were just going to do activities that we all could enjoy. So there we were, surrounded by spectacular natural beauty with adventure and discovery hidden behind every tree, while we sat in the dirt whittling sticks. Singing songs. Weaving baskets, watching the world drip by one excruciating second at a time.

“The baskets are fun! Look how nice your sister’s is turning out.”

“Can I make a really big one?” I asked.

“Of course! You can make whatever you want.”

“Okay I’m going to weave a coffin then. You can just bury me wherever.”

“Don’t even joke about that,” my father grunted.

“Or better yet, I’ll make one for Clara. If she’s too sick to do anything fun then she might as well —”

“Mark!” Mom that time. I’d crossed a line and I knew it, but I didn’t care. I was bored out of my mind. I missed my computer and my friends. I hated all this lovey-dovey family time. They always took her side about everything and gave her whatever she asked for, but if I ever wanted something I was just being selfish.

“I’m going to be in the woods if anyone needs me. As if.”

I heard mom start to chase me for a second, but dad stopped her to interject: “Stay close, okay? Don’t get lost.”

Getting lost didn’t seem like such a bad option at the moment. White-barked giants stretching as far as I could see, with mazes of fallen trees and branches that I could use to build forts. Lush grass and ferns to run through, craggy rocks to climb, meandering streams to jump — I can’t believe the rest of them sat eight hours in the car just so they can keep sitting around here. I marveled at the natural grandeur as I walked, mesmerized by the idea that this huge forest was all a single living thing. I decided to dig with a stick to get a look at the connected roots, but the ground was hard and the going was slow.

This would have been a lot easier if I’d had some help. When Clara and I were little, we used to do everything together. She was like my sidekick, always enthusiastically following me around leaping to attention whenever I had a mission for her. What was the point of playing games with yourself when no one was there to cheer your victories or mourn your defeats?

My frustration at the futility of the dig was quickly mounting, but I used that feeling as fuel to ram the stick down even harder. Out of breath, sweating and aching, I thrust the stick so hard that it snapped in two. I don’t know why that made me so angry, but it did. I dropped to my hands and knees and started digging with my fingers, hurling rocks and dirt clods around me in every direction. My fingers were accumulating cuts and scrapes, and I was about to give up when my hand suddenly broke through a thick clump of roots to reveal a hole in the ground.

Dirt and pebbles rained down the hole to disappear in the darkness below. It must have been deep too, because even with my ear to the ground I couldn’t hear anything land. Unwilling to return and admit defeat, I spent the next few hours widening the hole and trying to find a way to climb down. By around noon I was so filthy that I was practically indistinguishable from the earth I churned through. My fingers were openly bleeding in places, and the beating sun frowned down with disdain at my efforts. None of that mattered though, because I’d opened the hole wide enough to slip inside the yawning darkness.

I climbed down the network of roots which were matted as densely as a net. My phone’s flashlight prodded the darkness like a needle in an elephant, utterly underwhelming in the massive space I suddenly found myself within. The hidden cave was a converging point for the tendrils from the innumerable trees, which joined together here into larger roots, merging in turn to weave great networked tapestries which dwarfed the thin trees above the ground. I continued climbing downward along the widening roots, tempted to hide down here all day and freak out my family.

Below the cave, my route terminated in a small circular space, not much larger than my own body. It felt like being on the inside of an egg: completely encapsulated by the roots which were matted so densely now that they formed an impenetrable wall of wood. It was so quiet down here that I could hear my heart throbbing in my ears, my labored breathing a hurricane which fractured the stillness.

‘Can you hear them?’ my sister had asked last night, wide-eyed and serious.

Up above under the wide open sky with my family eating dinner? That question was child’s play. But here in this hidden kingdom under the earth? I placed my hand on a massive column and felt what she was talking about. This could have been growing before humans existed. It could have been touched by forgotten Gods or aliens who walked the Earth before history began. Or perhaps the Earth itself was living through these mighty pillars, lying dormant but for the quiet seething anger which slowly burned through the millennium.

The root was warm to the touch, and as I felt it, it was unmistakably feeling me in return. I had the unnerving feeling that a sound too deep for my ears to register was silently screaming around me. The feeling became more intense the longer I held on. I saw fire in my mind’s eye, running in infernal rivers from the depths of the world to drown the cities which infested the land like festering rot on clean skin. The root was getting hotter under my touch, and as much as I tried to clear my head, the thoughts returned — the decaying towers, the teaming crowds aimlessly running, the rivers of blood which flowed down crumbling streets.

I ripped my hand away and let go, panting for breath. This was better than ghosts. This was real. And all I could think about was showing it to Clara and watching her freak. I scrambled back up the roots, pulling myself hand-over-hand onto the surface to run the whole way back to the campsite.

“What in the world —” my mother started.

“Where’s Clara? I want to show her something.”

“She went to lie down for a little while. How did you get so filthy?”

But I didn’t wait. I sprang into her tent, practically dragging her to her feet while my parents protested from behind.

“Just for a second, okay? You can sleep anytime, but this is what we’re here for.”

There it was again. Mom and dad holding hands, clenching so tightly they shook. That didn’t matter though. All I could think about was Clara’s face when I showed her my secret discovery. Our parents offered to come with us, but I figured that would destroy the whole fun of the secret. I was pleasantly surprised that Clara was so willing to go — it seems like she didn’t want to do anything anymore.

“You heard it too,” she said the moment we were alone.

“Not heard. Felt.”

“This isn’t a trick, right? You’re not just making fun of me because I believe it?”

“When have I ever tried to trick you?” I put on my best facade of shocked-innocence. She snickered.

“How about when you wrote ‘soap flavor’ on the ice-cream box so you wouldn’t have to share?”

“That’s an isolated incident.”

“Or when you told me the cactus had soft spines like cat’s fur?”

“I didn’t think you’d just slap it.”

She laughed again, and we walked on in silence for a bit. She was obviously struggling, but she was just as obviously making an effort to hide it, so I didn’t say anything. It wasn’t much farther anyway.

“Up there, right around that grove. Anyway if I trick you so much, then how come you still believe me?”

She shrugged, catching my eyes for a second before turning to look where I was pointing. “I guess I don’t know how many more chances I’ll have to be tricked. I want to make the most of it while I still can.”

I didn’t know how to respond to that, so I kept walking.

“That’s why we’re here. You know that, right?” she asked.

I kept staring straight ahead.

“This might be our last chance for the whole family to be together before I…”

“It’s over here,” I interrupted, squatting down beside the hole. I expected her to say something sarcastic or to complain.

“Give me a hand, okay?” She didn’t even hesitate. Feet first, she began lowering herself down. I helped keep her steady while she climbed. I kept my eyes on our hands so I didn’t have to look at her face. I fully understood what she was saying, and I didn’t want her to say more. I didn’t start climbing after her until her feet had touched the cave floor.

“You’re right. It’s stronger down here,” she said.

“You haven’t seen anything yet. Come on.”

I continued leading to the point where the roots terminated in the enclosed root-egg. There wasn’t enough room for both of us to fit in the perfect nest, so I helped her climb in while I waited in the larger cave. Her fingers grazed the roots in silent reverence, hand jerking back from their warmth. That little smile glinted in the darkness, stretching into a euphoric grin as she touched the wood again to massage the wood.

“You feel it?” I asked. I knew she did, but I had to ask anyway because the silence was so heavy down here.

She simply smiled and closed her eyes. The sound of my rushing blood filled my ears again. I had to keep talking.

“What made you think it was calling for you?”

She wasn’t the one who answered though. It was that scream again, too deep to hear, but I felt the echo in every vibrating root. It came from everywhere — all the mighty forest bellowing in silence, all the unknown depths of the roots, all resonating with a single, persistent, throb. Even outside of the egg I could start to feel the colossal intent seep into my mind. Incessant, irrepressible thoughts, so vivid I might as well be seeing them with my eyes. Imagery of burning rivers bubbling up from the Earth to exhaust themselves in the open air, leaving behind an abyss so deep that it must pierce through the core of the planet.

“Clara? What’s going on? What do you see?” Even shining my light in my face, I could barely see it. All was fire and the bellowing howl, mounting in pitch just enough for me to actually hear the low rumble like an earthquake.

“Clara you have to get out of there. Something is going to happen.”

“I know. I’m making it happen.” The voice sounded so small and distant next to the enveloping presence. “We both need each other. “I need its enduring life, and it needs a body to guide its will.”

“Clara where are you? Quick grab my hand!” I fumbled to reach down to her, but the visions were too intense for me to see straight. My raw hands kept butting up against the roots.”

“Tell mom and dad that I didn’t die. That I’ll never die.”

Why couldn’t I find the opening? I’d been standing right over it a moment ago.

“Tell them I’ll be with them in the forest, even if they think themselves alone.”

It took me going down on my belly to finally realize what had happened. It wasn’t that I couldn’t find the hole — it’s that the hole didn’t exist anymore. The roots had moved, fully sealing Clara inside the earth.

“Clara! Can you hear me? Clara get out!”

“I am out, Mark.” The reply was so faint. “No more tricks between us. You’re the one who should be running.”

I’m not proud of the fact that I ran, scrambling back up the roots to pull myself onto the surface. Some might call it cowardice, but I know the certainty in her voice and I trusted her more than I trusted myself at that moment. Even above the ground, I could still feel the silent scream, so low and powerful that my entire body vibrated. Panting for breath on the surface, I started to scream with everything my ragged lungs would allow. I don’t know how long this went on for, but by the time I stopped, the forest was silent again.

The earth wasn’t shaking. The visions had cleared. All except for the hint of Clara’s face outlined in the bark of an aspen tree.